Burglar-alarm



M. GOLDSTONE.

BURGLAR ALARM.

APPLICATION F-ILED OCT. 8. I919.

Patented May 10, 1921.

/4- f I 2a A? f 45 A; 12 25 g stares PATENT r es.

' .GOLDSTONE, OF NEW HAVEN, CONNECTICUT.

, BURGLARALARM.

T 0 (ZZZ whom it may concern:

Be'it known that 1, MAX GoLDs'roNn, a

citizen of the United States, residing atN ew Haven, in the county ofNew Haven and State of Connecticut, have invented certain new and usefulImprovements in Burglar-. Alarms, of which the following is aspecification, reference being had therein to the accompanying drawings.

My invention relates to new and useful improvements in burglar alarms,and has particular reference'to that type of alarm that is attached toa'door.

It is the object of this invention, among other things, to provide adevice of this character thatmay be readily attached to and supported bythe door that will sound an alarm upon the turning of the knob, thatwill continue sounding until the knob is releasedfand further, to sodesign and construct the mechanism of the device that it maybe-manufactured atthe'minimum cost and require little or no skill in itsattachment.

To these. and other ends, my' invention V consists in the burglar alarm,having certain details of construction and combinations of parts, aswill be hereinafter described and more particularly pointed out in theclaims.

Referring tothe drawings, in which like numerals of referencedesignatelike parts i in the several figures;

' Figure 1 is a side elevation of my improved invention in operativerelation to a door which with the door knobs therein is shown in brokenlines;

Fig. 2 is a front elevation thereof with the.

bell mechanism removed; and r Fig.3 is a view showinga modificationofthe means for attachment to the knob;

In the embodiment of my invention I provide a base member 10, having inone edge thereof companion slots 12, through which project the screws 11by which said base plate is secured to the door. By the use of the.slots 12 the'screws 11 can remain -permanently in the door and thedevice readily detached therefrom by merely loosening the screws Holesfor the screws to pass through the base plate may be sub stituted forthe slots 12, if desired.

Fixed to the base member 10, is a bracket 13 having laterally projectingparallel arms 11. thereon ,at opposite ends thereof. "The base member 10and bracket 13 may be made integral within my invention. 1

Specification of Letters Patent. Patented pla 10, 1921.

Application filed October 8,1919. Serial No. 329,200.

through the upper arm 14, an ofiset portion 18 near its lower endanda'lug19 adjacent thereto. I

I By means of the nut 17 threaded on the shank 16, the vertical positionof the carrier 15 in relation to the base member 10 is variable, thespring 20' resisting the action of the nut 17 and keeping the carrier 15in its then lowermost positionr Fixed to thecarrier 15 by the screw 21is the plate 22 having slots 23 therein similar to trl' eslotsl2 andthrough which project the screws 2 1 that are threaded into the bellplate 25 secured to the-bell 26. By means of the screws 24am slots 23the bellmay be readily attachedto and detached from the plate 22. I i

The bell 26 having a plunger 27 with a head 28 thereon provides thepushing means i and is of the ordinary type and constitutes no part ofmy invention.

. Pivotally mounted on the lower end of the carrier 15 by the pintle 29is the lever 30 that is connected at its inner end with the lug 19 by aspring 31 and tothe door knob by the chain 32, spring33 and radial post34:. This radialpost may be secured to the knob in any desired manner,either by being forced therein whereby sufficient friction is providedto hold the same, or by threading or being made integral therewith. 7

Pivotally connected to one end of the lever 30 bythe screw 35 is aconnection lever ,36 having an upwardly turned portion 37 at one end anda finger arm 38 at the opposite'end and a stop lug 39 between its'ends,

which'engages the lever 30 and limits the movement of said connectionvlever 36 in relation tosaid lever 30.

In operation the device atesthe lever 30 -upon its mounting 29 movementraises the levers 30 and 36 so that the end portion 37 upon the lever36, which engages the head 28 of the plunger'27, moves said plungerinwardly and by reason thereof actuates the bell mechanism, which causesthe-bell to ring and sound'the alarm. As

soon as'the' knob 40 is released it returns to its original position,aswell as theflevers' and 36,' permitting the plunger 27'to be isattached to the inside of a door substantially. assho'wn, andtheslightest rotation of the knobs .40 actu V moved outwardly and releasingthe mechanism and the bell stops ringing.

A stop 44 on the lever 30 contacts with the carrier and limits themovement of the said lever in one direction.

The spring 33 is made slightly heavier than the spring 81 so that uponthe first rotation of the knob the spring 33 will not yield, butif acontinuous rotation is given to the knob the stop 44 limits the movementof the lever 30, and then the spring 33 yields and permits furthermovement of the chain 32 without adecting any of the parts with whichthe spring 33 is connected. Thus the slightest movement of the knobrings thealarm even-before the door is opened while the heavier spring33 accommodates such movement of the knob as is necessary to open thedoor.

Rotation of the knobs 40, will impart no movement to the plunger and thebell will not ring when the lever 36 is ,moved upon its pivot mounting35 until it eccupies substantially the dotted position shown in Fig. 2,wherein the end portion 37 thereof is moved out of alinement with thehead 28.

Of course, wire or other substance may be substituted for the chain 32if desired and in many ways the details of my invention may beconsiderably modified without departing from the spirit thereof.

This device is so light, and its bulk so small, and its attachment soconvenient, that it may be carried from place to place and attached todoors temporarily, as protection 'to the room occupant, in which case ifno radial post 34 is attached to the knob 40, a substitute can beprovided through the clamp 41, having a screw 42 therein -which providesmeans for connecting the chain 32 therewith. This clamp is secured uponthe knob of the door through the'action of the screw 43, in a wellknownmanner. y

. By manipulation of the nut 17, the rela tive position of the end 37 ofthelever 36 with the plunger 27 may be varied so as to vary thesensitiveness of the device. That is, if the said lever end 3'? is incontact with the plunger'head 28 when the parts are at rest, th bellwill ring upon the slightest movement of the knob, while if it is aslight distance therefrom, sufficient movement of the knob tobring saidend in contact, is permissible before the bell will ring and in otherways the adjustment of the carrier is quite desirable. By rotation ofthe nut, so

as to move the carrier to its approximate up position, the relation ofthe lever 36 and -plunger 27 is such that the alarm will con tinue tosound, if once started until manually released.

This device is attached to the door itself and is thus supported, sothat its weight is gagement in one of its not upon the door knob, and istherefore much more sensitive in action, and less liable to bediscovered by delicate manipulation of the knob to ascertain itspresence. Unsuccessful attempts have heretofore been made to accomplishthis result, more par ticularly by supporting the device in the key holeof the lock or lock plate, but this prevents the insertion of the keyand hence is very objectionable.

Having described my invention, what I claim as new and desire to secureby Letters Patent, is:

1. A burglar alarm comprising a base member fixed relatively to the doorknob,

an alarm bell, actuated through a push mechanism, detachably secured tosaid carrler member, a rock lever pivotally connected with said carriermember and having apart thereon in contact with said push mechanism,andan operative connection betweenthe door knob and said rock lever;said connection being such that a limited r0- tation of said door knobactuates said alarm mechanism through said rock lever and after placedin operative position, the connection yields in part without impartingfurther movement to the rock lever.

A burglar alarm comprising a base member to be separablysecured to adoor, having a carrier member adjustable thereon, an alarm bell,actuated through a push "mechanism, detaohably secured to said carriermember, a rock lever pivotally connected with said carrier member andhaving a part thereon in contact with said push mechanism, an operativeconnection between the door knob and said rock lever, said connectionbeing such that a limited rotation of said door knob actuates said alarm1nechanism through said rock lever and after placed in operativeposition, the connection yields in part without imparting furthermovement to the rock lever, and a member mounted upon said rock lever soas to be movable relatively thereto, and having enpositions withsaidpush mechanism. 4. Aburglar alarm comprising a base member designed tobe separably secured to a door, having a carrier member adjustableerative connection between the door knob I and said rock lever, saidconnection being such that a limited rotation 01: said knob actuatessaid alarm'mechanism through said rock lever and after placed inoperative position said connection yields without imparting furthermovementto said rock lever; and a yielding connection between oneend ofsaid rock lever and said carrier member.

5(A burglar alarm comprising a base member fixed relatively to the doorknob, having a carrier member adjustable relatively thereon, yieldingmeans for resisting the adjustment 01": said car ier member, a plateconnected with said carrier member, an alarm bell actuated through apush mechanism detachably connected with said plate, a rock leverpivotally connected with the said carrier member, having a stop thereonto limit its movement in one direction, a member pivotally connectedwith said rock lever and movable relatively thereto, and in one of itsrelative positions actuating said push mechanism during'the movement ofsaid rock lever, means 101' connecting said rock lever with the doorknob, actuating said rock lever during the first portion of the rotationof said door knob andyielding during the remainder of said movement.

6. A burglar alarm comprising base member fixed relatively to the doorknob, having a carrier member adjustable there- 'on substantiallyparallel with the door, 'an

alarm bell mounted on said carrier member and'actuated through a pushmechanism, a lever having a part thereon in contact with said pushmechanism and pivotally connected with the carriermem'ber, and anoperative connection between the door knob and member, whereby movementof the door knob actuates said push meclianism through the swinging ofsaid lever, said connection having a yielding portion and an unyleldingportion, the relative strength of said yielding portion being such thatit will not yield lllltll said push mechanism has been actuated.

7. A burglar alarm comprising a base member fixed relatively to the doorknob,

having a carrier member adjustable relativel thereon ielding' means forresistin J a L. a the ELClJUStDlGIll] or said carrier member, a plateconnected with said carrier member, an

alarm bell actuated through a push mechanism detachably connected withsaid plate,

a rock lever pivotally connected with the said carrier member, having astop thereon to limit its movement in one direction, a

member pivotally connected with said rock lever and movable relativelythereto, and in one of its relative positions actuating said pushmechanism during the movement of said rock lever, means for limiting therotation of said member in one direction relatively to said rook lever.

In testimony whereof, l have hereunto atfixed my slgnature. 1

MAX eoLDsToNn

